function changeTable(direction) {
			var idCourant = 0;
			var lst_table = document.getElementsByTagName("table");
			for (i=0; i<lst_table.length; i++){
				if (lst_table[i].style.display=="block"){
					idCourant = lst_table[i].id;
				}
			}
			
			if(direction == "-"){
				document.getElementById(idCourant).style.display="none";
				var j = idCourant.substr(idCourant.length-1,1);
				if(j<=1){
					j = lst_table.length;
				}
				var newPos = idCourant.substr(0,idCourant.length-1).concat(--j);
				document.getElementById(newPos).style.display="block";
			}else{
				document.getElementById(idCourant).style.display="none";
				var j = idCourant.substr(idCourant.length-1,1);
				if(j>=lst_table.length-1){
					j = 0;
				}
				
				var newPos = idCourant.substr(0,idCourant.length-1).concat(++j);
				document.getElementById(newPos).style.display="block";
			}
		}
